docs: def insert(self, table, columns, rows):
          """
          Insert several rows with executemany. Return a cursor.
          """
          cursor = self.conn.cursor()
          if len(rows):
              templ, _args = match('INSERT INTO ?s (?S) VALUES (?X)',
                                   table, columns, rows[0])
              cursor.executemany(templ, rows)
          return cursor